The Cougar 140mm x 25mm CFD Series LED Fan features an innovative blade design with nine dual-layer rigid blades generating more powerful airflow, air pressure & decrease wind shear noise. The fan itself is outfitted with an anti-vibration pad design that further eliminates unwanted noise from vibration. The hydro-dynamic bearings used make this fan run more smoothly with no friction and increases durability and lifespan as well.